Wheel assembly

ABSTRACT

A wheel assembly especially suitable for use on large heavy refuse carts. The wheel assembly includes an axle which has been heat treated and plated to provide a central core, an outer skin on the central core of substantially increased strength and hardness, and a chromium plating on the outer skin, and the associated hub of the wheel has been heat treated to provide an annular interior skin in journalling association with the axle having an increased hardness and strength as compared to the main body of the hub. The chrome plating on the axle has a hardness in excess of the hardness of the interior hardened skin of the wheel hub. The wheel assembly is mounted between spaced parallel mounting plates on the associated refuse cart with the ends of the axle passing through apertures in the lower ends of the mounting plates and with the assembly held in place between the mounting plates by a bolt carrying a washer and threadably engaging a blind bore in one end of the axle so as to position an end plate on the other end of the axle against the outboard face of the outboard mounting plate. A pair of seals are provided at each end of the hub of the wheel and an annular grease groove is provided in the hub inboard of each pair of seals.

BACKGROUND OF THE INVENTION

This invention relates to wheel assemblies and more particularly towheel assemblies especially adapted for use with large carts such asrefuse carts.

With the ever increasing industrialization of our society, the need fora quick and efficient means of removing waste for ultimate disposal hassteadily increased. The industry that has grown up to service this needhas largely evolved in two directions. For relatively lighter and/orlower bulk waste disposal requirements, containers are provided at theuser facility which, when filled with waste matter, are emptied into arefuse truck by a suitable hoisting mechanism and then replaced inposition at the user facility to receive more refuse. In situationsrequiring larger volumes or heavier weights of refuse, the so-called"roll off" container or cart has been used. The roll off carts typicallyprovide a capacity of between 12 and 40 cubic yards; may be used inassociation with an end compactor at the user facility; and aretypically picked up and carried away when full on a custom vehicle, inpiggyback style, with the vehicle carrying away the filled cart alsodelivering a new, empty cart to the user facility prior to pickup of thefilled cart. These large refuse carts, in the course of loading andunloading onto the associated custom vehicle, receive considerableabuse. Since they must be dragged considerable distances both during theplacement and the removal operations, they are typically provided withwheel assemblies at the four corners of the cart. The wheel assembliessustain heavy abuse, not only because of the extremely heavy loads beingcarried in the carts, but also by virtue of the rough handling and therough terrain over which the carts are dragged. The wheel assemblies inthe past have generally comprised relatively standard designs in which asimple wheel is journalled on a hot rolled mild steel axle extendingbetween parallel mounting plates on the corners of the cart. Due to therelatively unsophisticated design of the wheel assemblies and theextremely heavy abuse that the wheel assemblies receive, the wheelassemblies have become extremely high maintenance items. It is notunusual, for example, for the wheel assemblies to wear out to a point ofbeing unusable in as short a time as three months. Typically the wheelassemblies are rebuilt, placed back in service, and then again rebuiltafter which they again quickly wear out. A typical average total life ofa wheel assembly, including several rebuilds, is about two yearswhereafter the entire wheel assembly must be replaced. In addition tothe considerable expense associated with with rebuilding and ultimatelyreplacing the wheel assemblies, the wheel assemblies may becomedislodged during road transport on the associated vehicle and run wildand at high speed along the roadway, creating a potential for seriousdamage to other vehicles and/or personal injury. Further, since thesecontainers are typically used in conjunction with an on site compactor,the cart can no longer be set at the proper height required for latchingonto the compactor after it has lost a wheel assembly. Further, acontainer with a lost or severely damaged wheel assembly inflicts severedamage to the associated asphalt pavement onto which it is placed orover which it is dragged during the loading or unloading operation.Further, when a cart is taken out of service because of a damaged wheelassembly the cart must be brought into the main depot for maintenanceand repair, resulting in time loss by the driver of the associatedvehicle and revenue loss because the cart is out of service.

Various attempts have been made to introduce more sophistication intothe wheel assemblies of these refuse carts in order to reduce themaintenance problem. For example, various attempts have been made toincorporate grease fittings so that lubrication can be added to the huband axle assembly; other attempts have involved the use of roller orball-type bearings in the wheel assemblies; and other attempts haveinvolved the use of plastic or bronze bushings in the wheel assemblies.However, none of these attempts to improve the durability of the wheelassemblies has met with any degree of commercial success. Specifically,in the case of the lubricated wheel assemblies, the truck drivers areoften remiss in greasing the axles on a regular schedule, the greasefittings become damaged and cannot be replenished with grease, or thegrease fittings accumulate sand and dirt making it difficult orimpossible to snap on the grease gun fitting or, even if greasing ispossible, the greasing operation pumps in sand and dirt which in turncauses high abrasion failure of the axle and hub. In the case of theroller or ball-type bearing designs, it has been found that theextremely high gross vehicle weights and extremely high shock loadforces encountered by these refuse carts causes immediate or eventualcatastrophic failure to the internal bearing parts. In the case of theplastic or bronze bushing designs, the extremely high gross vehicleweights cause material flow-type deformation with resultant immediate oreventual failure of the wheel assembly.

SUMMARY OF THE INVENTION

This invention is directed to the provision of an improved wheelassembly especially suitable for use with refuse carts.

More particularly, this invention is directed to the provision of awheel assembly for use with refuse carts which will provide many timesthe useful life of the wheel assemblies presently employed on the refusecarts.

The wheel assembly according to the invention includes a pair of flangeplates adapted to be rigidly secured to a respective corner of therefuse cart and extend downwardly from the main body of the cart inparallel spaced relation; and aperture in the lower end of each flangeplate; an axle passing slidably through the apertures in the flangeplates and presenting a journal portion of round cross section betweenthe plates; and a wheel comprising a tubular hub positioned between theflange plates and journalled on the axle journal portion, a rim, andmeans interconnecting the rim and hub in concentric relation. Thissimple arrangement provides an inexpensive but highly durable wheelassembly construction that is especially suitable for handling the highgross vehicle loads of the associated refuse carts.

According to a further feature of the invention, the axle journalportion and the hub, at their annular interface, are formed of differentmaterials. This arrangement improves the wear qualities of the assembly.

According to a further feature of the invention, the axle journalportion, in cross section, comprises a metallic central portion and anannular outer layer forming a plating on the central portion having ahardness greater than that of the central portion. This hard platingfurther improves the wearability of the wheel assembly.

According to a further feature of the invention, the outer layercomprises a chromium layer. The use of a chromium layer further improvesthe wearability of the wheel assembly.

According to a further feature of the invention, the central portion ofthe axle journal portion is heat treated prior to application of thechromium layer to form a relatively soft core and a relatively harderouter skin directly beneath the chromium layer. This hard skin beneaththe chromium layer provides structural strength for the chromium layerto preclude "punch through" damage to the chromium layer.

According to a further feature of the invention, the annular layer ofthe axle immediately underlying the hard outer skin has an averagehardness substantially exceeding the hardness of the core of the axlebut less than the hardness of the outer skin. This relatively hardintermediate layer provides support to the hard outer skin and coactswith the outer skin to provide exceptional structural integrity for theaxle.

According to a further feature of the invention, the central core of theaxle has a hardness greatly exceeding the hardness of a typical carbonsteel so as to further add to the structural integrity of the axle.

According to a further feature of the invention, the hub is formed of acarbon steel and is heat treated to form a relatively soft annular mainbody portion and a relatively hard annular skin on the annular interiorperiphery of the main body portion. The relatively hard annular skin onthe interior periphery of the hub portion coacts with the chromiumplating on the axle to further enhance the wearability of the wheelassembly.

According to a further feature of the invention, the annular interiorskin of the hub has a hardness less than that of the chromium layer onthe axle. This specific relative hardness at the interface of the axleand hub further improves the wearability of the wheel assembly.

According to a further aspect of the invention, the axle journalling thehub has a length exceeding that of the hub so as to project axiallybeyond the hub at each end of the hub to provide mounting end portionsfor passage through aligned apertures in the spaced mounting plates onthe associated body structure of the refuse container to mount the wheelassembly on the associated body structure and rollably support the bodystructure; a threaded bore is provided in one end of the axle; a bolt isprovided which is sized to be threaded into the threaded bore; a washeris provided having an inner diameter sized to pass the bolt and an outerdiameter greater than the diameter of the axle; and a plate member isrigidly secured to the other end of the axle and includes a portionextending radially outwardly beyond the axle.

This wheel assembly construction allows the wheel assembly to be mountedon the associated body structure by positioning the hub between the bodystructure mounting plates, passing the one end of the axle through theaperture in one mounting plate, through the hub, and through theaperture in the other mounting plate to bring the plate member intoengagement with the outboard face of the one mounting plate, andthreading the bolt with the washer thereon into the threaded bore in theaxle to bring the washer into engagement with the outboard face of theouther mounting plate. Removal of the wheel assembly for repair orreplacement is similarly readily accomplished.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic perspective view of a refuse cart embodying theinvention wheel assembly;

FIG. 2 is a cross-sectional view of one of the wheel assemblies employedin the refuse cart of FIG. 1;

FIG. 3 is an enlarged cross-sectional view of the invention wheelassembly;

FIG. 4 is a cross-sectional view of a hub employed in the inventionwheel assembly;

FIG. 5 is a detailed view taken within the circle 5 of FIG. 3;

FIG. 6 is a view looking in the direction of the arrow 6 in FIG. 2;

FIG. 7 is a cross-sectional view taken on line 7--7 of FIG. 3; and

FIG. 8 is a detailed view taken within the circle 8 of FIG. 7.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The refuse cart 10 as seen schematically in FIG. 1 includes a bodystructure 12 of generally boxlike configuration with a closed top 12a,and an opening or door 12b in the rear end wall 12c of the cart. A wheelassembly 14 is provided at each corner of the cart to rollably supportthe cart. As previously indicated, the refuse cart 10 is intended to becarried in piggyback fashion on an associated vehicle to the user site,unloaded from the vehicle, placed in a user position in association withan end compactor with opening 12b juxtaposed to the compactor, andthereafter loaded back onto the associated vehicle after it has beenfilled with refuse.

Each wheel assembly 14 includes a pair of flange or mounting plates 16,an axle assembly 18, and a wheel assembly 20.

Plates 16 are formed of a suitable steel and are welded in spacedrelation to the underside of the body structure 12 of the cart with twoplates provided at each corner of the cart. Each plate tapers inwardlyand downwardly and includes a circular aperture 16a in the lower end ofthe plate.

Axle assembly 18 includes an axle 22, an end plate 24, a washer 26, anda bolt 28.

Axle 22 is manufactured from a carbon steel stock containing, forexample, 0.23% carbon, 0.80% magnesium, 0.23% silicon, 0.50% nickel,0.50% chrome, and 0.20% molybdenum. The axle is machined to printspecification and a blind threaded bore 22a is provided in one end ofthe axle. After machining, the axle is subjected to a temperature of1,650 degress F. in an atmosphere of endothermic hydrocarbon generatorgas for a period of four hours, then allowed to cool to 1,425 degrees F.The axle is then quenched in 70 degree F. oil. After removing the axlefrom the quench oil, it is subjected to a 350 degree F. bake for aperiod of two hours. This heat treatment process creates an axle having,in cross section and as best seen in FIGS. 7 and 8, a relatively softcentral core 22a, a transient layer 22b of gradually increasinghardness, and an extremely hard annular outer skin 22c. As compared to astarting tensile strength of approximately 95,000 psi (12 R_(c)), theheat treated axle may have an internal core strength of 175,000 psi (38R_(c)) which gradiently increases in layer 22b to 325,000 psi (60 R_(c))at the inner periphery of the skin 22c and maintains at 60 R_(c)throughout the thickness the skin 22c. For an axle having a diameter of1.25 inches, layer 22b may have a thickness of approximately 0.06 inchesand skin 22c may have a thickness of approximately 0.04 inches. The axleis then surface ground on the outside diameter to an exact size within0.0005 inches on the diameter and is thereafter electroplated withchromium to a thickness of 0.0005 or a total of 0.0010 on the diameter.The chromium layer or plating is seen at 22d in FIGS. 7 and 8. Chromiumlayer 22d provides an R_(c) of approximately 63. The axle is thensubjected to a 350 degree F. bake to remove surface hydrogen generatedby the electroplating process and absorbed by the axle surface. Thisrelieves surface embrittlement. The choromium surface is then polishedto a 16 microinch finish to give all parts a smooth running surface.

In the completed axle 22, the chromium layer 22d provides wearability atthe axle/hub; the skin 22c provides structural strength for the chromiumlayer to preclude "punch through" damage to the chromium layer; thegradient layer 22b provides support for skin 22c and coacts with skin22c to provide exceptional structural integrity for the axle; and thehardened central core 22a provides support for gradient layer 22b andcoacts with the other layers to further add to the structural integrityof the axle.

End plate 24 is then welded onto the end of the axle remote from thethreaded bore 22a to complete the axle assembly. Axle 22 has a lengthsuch that, when fitted in apertures 16a in mounting plates 16 with endplate 24 positioned against the outboard face of the outboard mountingplate 16, the annular end face of the axle around bore 22a issubstantially flush with the outboard face of the inboard mountingflange 16.

Wheel 20 includes a central hub 30, a pair of wheel disks 32, and rim34. The wheels at the rear of the cart are significantly wider than thewheels at the front of the cart to accommodate the differing loadsencountered at the front and rear of the cart.

Wheel hub 30 is tubular and has a central bore 30a sized to slidablypass axle 22 with a journal fit; has a length such that it fits looselybetween the inboard faces of the mounting plate 16; and is preferablymanufactured from a carbon steel containing 0.25% carbon and 0.75%maganese. The hub is machined to print specifications, adding seal endpockets 30b formed as counterbores on each end of the hub, lubricationgrooves 30c formed as further counterbores between each seal pocket 30band central bore 30a, and lubrication reservoir grooves 30d spacedinboard from each counterbore 30b. After machining, the hub is preheatedin an air furnace to 750 degrees F. and is then transferred into aspecially formulated salt bath containing 50% potassium cyanide and 50%potassium cyanate, at 1,060 degrees F. The hub remains in the bath fortwo hours. The hub is then removed from the bath, allowed to cool to 700degrees F. and quenched in oil, after which time it is removed andcleaned. This processing provides a hub which, as best seen in FIGS. 7and 8, includes an annular core 30e which essentially retains itsuntreated tensile strength of 80,000 psi (5 R_(c)), and a hardnongalling interior peripheral skin 30f having a tensile strength of285,000 psi (55 R_(c)). For a hub having a nominal outer diameter of 2.0inches, skin 30f may have a thickness of 0.0005 inches. Skin 30fcomprises a carbon bearing epsilon iron nitride containing no brittleFe₂ N. The heat treated hub is then passed through central apertures inthe disks 32, the disks are welded to the hub, and the rim 34 is weldedto the outer periphery of the disk 32 to form the wheel. Disks 32 arepreferably inset with respect to the rim 34 so that the rim overlaps thedisk at each side face of the wheel.

Prior to installing the wheel assemblies on the refuse cart, a greaseseal 36 and a wiper or contaminate excluder seal 38 are fitted into eachseal counterbore 30b. Grease seal 36 may comprise, for example, a sealavailable from the Grover Piston Ring Division of FluorocarbonCorporation of Milwaukee, Wisconsin as U-Cup Style No. 15, and seal 38may comprise, for example, a seal available from the same source asU-Pack Style No.30. As best seen in FIG. 5, the seals are maintained inposition in counterbore 30b by a seal retainer 40 bearing against a sealretaining split ring 42 received in a groove 30g adjacent the outboardend of each counterbore 30.

Following positioning of the seals 36, 38 in the counterbores 30b,lubricant is provided in lubrication grooves 30c and 30d; bore 30a andaxle 22 are heavily lubricated; wheel 20 is positioned between plates16; and the threaded bore end of axle 22 is passed through the aperture16a in the outboard mounting plate 16 and through the central bore 30aof hub 30 for passage through the aperture 16a of the inboard mountingplate 16. As previously indicated, axle 30 is sized so that the threadedend of the axle reaches a position flush with the outboard face of theinboard mounting plate 16 at such time as end plate 24 moves intoengagement with the outboard face of the outboard mounting plate 16.Washer 26 and a lock washer 44 are now placed over bolt 28 and bolt 28is threaded into threaded bore 22a to complete the assembly of the wheelassembly to the refuse cart. As best seen in FIG. 6, axle 22 isprecluded from rotating relative to mounting plates 16 by engagement ofa flat side face 24a of end plate 24 with a confronting side face 42apresented by a key 42 welded to the outboard face of the outboardmounting flange 16.

Removal of the wheel assembly for repair or replacement is readilyaccomplished by simply removing bolt 28 and sliding the axle assembly tothe left as viewed in FIG. 3 to withdraw the axle from the mountingplates and allow the wheel 20 to be removed from between the mountingplates.

The invention wheel assembly, in actual test, as compared to wellestablished data with respect to the standard hot rolled mild steelwheel assemblies long in use in association with refuse carts, hasincreased axle strength by an estimated factor of 3.5 and has increasedwearability of the wheel assemblies many times. More specifically,whereas the prior art wheel assemblies typically require rebuildingevery three months and have been totally useless after an average lifeof two years, the invention wheel assemblies have required nomaintenance during a two-year period of test usage and, followingdisassembly after the two-year period of test usage, have shown nosignificant wear.

Whereas a preferred embodiment of the invention has been illustrated anddescribed in detail it will be apparent that various changes may be madein the disclosed embodiment without departing from the scope or spiritof the invention. For example, at least in certain applications, plating22d, rather than being formed of chromium, may comprise a nickel layerthat is deposited on the axle and then baked to an R_(c) ofapproximately 63.

I claim:
 1. A wheel assembly for use at the four corners of a cart torollably support the cart, said wheel assembly comprising:(A) a pair offlange mounting plates adapted to be rigidly secured to a respectivecorner of the cart and extend downwardly from the main body of the cartin parallel spaced relation; (B) an aperture in the lower end of eachmounting plate; (C) an axle passing slidably through said apertures insaid mounting plates and presenting a journal portion of round crosssection between said plates; (D) a wheel comprising a tubular hubpositioned between said mounting plates and journalled on said axlejournal portion, a rim, and means rigidly interconnecting said rim andsaid hub in concentric relation; (E) means defining an annular lubricantreservoir along the annular journal interface of said hub and said axlejournal portion; and (F) an elastomeric annular seal at each end of saidinterface at opposite sides of said annular lubricant reservoir.
 2. Awheel assembly according to claim 1 wherein:(F) said axle journalportion and said hub, at their annular interface, are formed ofdifferent materials.
 3. A wheel assembly according to claim 2wherein:(G) said axle journal portion in cross section comprises ametallic central portion and an annular outer layer forming a plating onsaid central portion having a hardness greater than that of said centralportion.
 4. A wheel assembly according to claim 3 wherein:(H) saidcentral portion is formed of an alloy steel; and (I) said outer layer isformed of a non-ferrous metallic element.
 5. A wheel assembly accordingto claim 4 wherein:(J) said central portion is heat treated prior toapplication of said outer layer to form a relatively soft core and arelatively hard outer skin directly beneath said outer layer.
 6. A wheelassembly according to claim 5 wherein:(K) said outer layer is formed ofsubstantially pure chromium.
 7. A wheel assembly according to claim 5wherein:(K) said hub is formed of carbon steel and is heat treated toform a relatively soft annular main body portion and a relatively hardannular skin on the annular interior periphery of said main bodyportion.
 8. A wheel assembly according to claim 5 wherein:(K) saidannular interior skin of said hub has a hardness less than that of saidouter layer on said axle.
 9. A wheel assembly according to claim 8wherein:(L) said outer layer on said axle is formed of substantiallypure chromium.
 10. A wheel assembly comprising:(A) an axle comprising arelatively soft alloy steel core, a relatively hard alloy steel skinsurrounding said core, and a non-ferrous plating surrounding said hardskin; and (B) a wheel including an annular hub journalled on said axleand comprising a relatively soft carbon steel annular main body portionand a relatively hard annular skin on the annular interior periphery ofsaid main body portion.
 11. A wheel assembly according to claim 10wherein:(C) said non-ferrous plating is a chromium plating; and (D) saidchromium plating has a hardness greater than the hardness of saidannular interior skin of said hub.
 12. A wheel assembly comprising:(A) awheel including a unitary one piece hub having a bore extending with asubstantially uniform diameter from end to end of said hub and includinga cylindrical central portion intermediate the ends thereof, a rim, andmeans rigidly interconnecting said rim and said hub in concentricrelation; (B) an axle positioned within said hub bore, having a diameterapproximating the diameter of said bore, having a direct annular bearinginterface with said bore including said central portion thereof, andhaving a length exceeding that of said hub so as to project axiallybeyond hub at each end of said hub to provide mounting end portions forpassage through aligned apertures in spaced mounting plates on anassociated body structure to mount said assembly on the associated bodystructure and rollably support the body structure; (C) a threaded borein one end of said axle; (D) a bolt sized to be threaded into saidthreaded bore and having a head; (E) a washer having an inner diametersized to pass said bolt and an outer diameter greater than the diameterof said axle, said washer being sized and configured to allow theradially inner portion thereof to be moved into abutting engagement withsaid one end of said axle in response to threading of said bolt intosaid threaded bore to position the radially outer portion thereofradially outwardly of said axle; and (F) an end plate member rigidlysecured to the other end of said axle and including a portion extendingradially beyond said axle and having an inboard face spaced axiallyoutboard from the confronting outboard face of said hub, whereby saidwheel assembly may be mounted on the associated body structure bypositioning said hub between the body structure mounting plates, passingsaid one end of said axle through the aperture in one mounting plate,through said hub, and through the aperture in the other mounting plateto bring said inboard face of said end plate member into engagement withthe outboard face of the one mounting plate, and threading said boltwith said washer thereon into said threaded bore to bring said radiallyouter portion of said washer into proximity to the outboard face of theother mounting plate and bring said radially inner portion of saidwasher into abutting engagement with said one end of said axle.
 13. Awheel assembly according to claim 12 wherein:(G) said assembly furtherincludes means for precluding rotation of said axle relative to themounting plates.
 14. A wheel assembly according to claim 13 wherein:(H)said rotation precluding means includes a flat surface on said platemember adapted to coact with a flat surface defined on the outboard faceof the one mounting plate.
 15. A wheel assembly for use at the fourcorners of a cart to rollably support the cart, said wheel assemblycomprising:(A) a pair of flange mounting plates adapted to be rigidlysecured to a respective corner of the cart and extend downwardly fromthe main body of the cart in parallel spaced relation; (B) an aperturein the lower end of each mounting plate; (C) an axle passing slidablythrough said apertures in said mounting plates and presenting a journalportion of round cross section between said plates; and (D) a wheelcomprising a tubular hub positioned between said mounting plates andjournalled on said axle journal portion, a rim, and means rigidlyinterconnecting said rim and said hub in concentric relation; (E) saidaxle journal portion and said hub, at their annular interface, beingformed of different materials; (F) said axle journal portion in crosssection comprising an alloy steel central portion and a non-ferrousmetallic annular outer layer forming a plating on said central portionhaving a hardness greater than that of said central portion; (G) saidcentral portion being heat treated prior to application of said outerlayer to form a relatively soft core and a relatively hard outer skindirectly beneath said outer layer; and (H) said central portion furtherincluding an annular intermediate layer underlying said hard outer skinand having a hardness less than the hardness of said outher skin butgreater than the hardness of the inner core of the axle.
 16. A wheelassembly according to claim 15 wherein:(K) said axle is manufacturedfrom an alloy steel; (L) said inner core has a hardness greatlyexceeding the hardness of the untreated alloy steel; and (M) saidintermediate layer has a hardness gradually increasing, moving radiallyoutwardly, from the hardness of said inner core to the hardness of saidouter skin.
 17. A wheel assembly comprising:(A) a wheel including a hub,a rim, and means rigidly interconnecting said rim and said hub inconcentric relation; (B) an axle journalling said hub and having alength exceeding that of said hub so as to project axially beyond saidhub at each end of said hub to provide mounting end portions for passagethrough aligned apertures in spaced mounting plates on an associatedbody structure to mount said assembly on the associated body structureand rollably support the body structure; (C) a threaded bore in one endof said axle; (D) a bolt sized to be threaded into said threaded boreand having a head; (E) a washer having an inner diameter sized to passsaid bolt and an outer diameter greater than the diameter of said axle;and (F) an end plate member rigidly secured to the other end of saidaxle and including a portion extending radially beyond said axle; (G)said axle comprising a relatively soft alloy steel core, a relativelyhard alloy steel skin surrounding said core, and a non-ferrous platingsurrounding said skin; (H) said hub comprising a relatively soft carbonsteel annular main body portion and a relatively hard annular skin onthe annular interior periphery of said main body portion.
 18. A wheelassembly according to claim 17 wherein:(H) said non-ferrous plating ischromium plating; and (I) said chromium plating has a hardness greaterthan the hardness of said annular interior skin of said hub.
 19. A wheelassembly according to claim 1 wherein two annular lubricant reservoirsare provided along said annular journal interface between said sealswith each reservoir positioned proximate an end of said annular journalinterface. 236